INFECTIONS IN NEONATES DELIVERED AT TERM ARE ASSOCIATED WITH INCREASED SERUM LEVELS OF ICAM-1 AND E-SELECTIN

All newborn infants consecutively admitted to the Neonatal Intensive C are Unit (NICU) at the University Hospital of Trondheim during 1993 we re eligible to participate in the study. In total, 241 neonates were i ncluded, for whom anamnestic, clinical and laboratory characteristics were recorded. Peripheral blood was retrieved at admittance, and serum levels of soluble intercellular adhesion molecule-1 (ICAM-1), vascula r cell adhesion molecule-1 (VCAM-1) and E-selectin were determined. Ne wborn infants were classified as infected or non-infected according to selected criteria, and 24 newborn infants fulfilled the criteria of h aving an infection, whereas 168 newborn infants were classified as non -infected. ICAM-1, VCAM-1 and E-selectin were detected in all neonatal samples. Serum concentrations of E-selectin varied by gestational age (GA), higher levels were found in non-infected term (GA greater than or equal to 37 weeks) neonates (n = 53) than in those (n = 115) delive red prematurely (GA < 37 weeks) without infection (p < 0.0001), wherea s ICAM-1 and VCAM-1 concentrations did not differ between groups of no n-infected term and preterm newborn infants. Similarly, newborn infant s delivered at term (n = 16) demonstrated higher levels of E-selectin than premature infants (n = 8) in association with infection (p < 0.00 1). Both ICAM-1 and E-selectin were increased in term newborn infants with infection (n = 16) compared to the non-infected term group (n = 5 3)(both p < 0.01), whereas VCAM-1 concentrations did not differ betwee n the two groups. In the premature groups of infected (n = 8) and non- infected (n = 115) neonates, no differences in ICAM-1, VCAM-1 and E-se lectin concentrations were observed. The use of ICAM-1 concentration ( cut-off level: 250 mu g l(-1)) as a diagnostic test for infection in t erm neonates yielded a sensitivity of 80% and a specificity of 61%, wh ereas a sensitivity of 70% and a specificity of 79% were found when E- selectin concentration (cut-off level: 150 mu g l(-1)) was used. Concl usively, increased shedding of soluble ICAM-1 and E-selectin is one co mponent of infection-induced neonatal immune response after full-time pregnancies. Our data suggest that the ability of increased shedding o f soluble ICAM-1 and E-selectin molecules is developed during the fina l weeks of pregnancy. Assessment of ICAM-1 and E-selectin concentratio ns may be used as diagnostic tools with a high sensitivity and a moder ate specificity in term neonates suspected of infection.